Device for transforming the movement for an electronic watch



June 24, 1969 M. HETZEL 3,451,280

DEVICE FOR TRANSFORMING THE MOVEMENT FOR AN ELECTRONIC WATCH Filed April 4. 1966 FIG.1

United Patent Claims priority, application Switzerland, July 29, 1965,

10,667 65 Int. Cl. F16h 27/02; G04c 5/00 US. Cl. 74-142 6 Claims ABSTRACT OF THE DISCLOSURE This disclosure concerns a device for transforming oscillatory movement of a resonator for an electronic Watch into a continuous rotatory movement in which a click is rigid with the resonator driving the ratchet wheel, there being a first magnetized wheel adapted to be rotated by the ratchet wheel and a second magnetized wheel adapted to be rotated magnetically by the first magnetized wheel, the first and second magnetized wheels being mechanically separated from each other so that one of the magnetized Wheels can rotate independently of the other magnetized wheel, the first wheel having a lesser moment of inertia than the ratchet wheel but a greater thickness.

, In electronic watches comprising a mechanical resonator the oscillating movement of the resonator is generally transformed into a rotary movement for driving the gear train, by means of a click cooperating with a ratchet wheel, constituting the first wheel of the dial train. The transformation of the movement is accompanied by a reduction of the frequency, the resonator operating at a frequency relatively high. In order to obtain a supple coupling between the resonator and the wheels WhlCh follow it, so as to permit the movement to be stopped while setting the hour, without disturbing appreciably the oscillation of the resonator, it has been proposed to use a double click constituted by a first ratchet wheel driven by a click rigid with the resonator, the first ratchet wheel carrying a cam driving elastically a lever having at Its other end a second click driving a second ratchet Wheel constituting the first wheel of the movement.

This device, which has also the advantage of constituting a mechanical filter hindering the transmission of the jerky advance of the first ratchet wheel to the members of the movement, has nevertheless the major disadvantage, other than its complexity, of only attaining a relatively small efiiciency, of the order of 30% The present invention has for its object to provide a device for transforming the oscillating movement of a resonator of an electronic watch into a movement of continuous rotation without jerks, having the same advantages as the double click, but of simpler construction and of greater efiiciency. This device is characterised in that it comprises a click rigid with the resonator driving a ratchet wheel, a first magnetized wheel adapted to be rotated mechanically by the ratchet wheel, and a second magnetized wheel adapted to be rotated magnetically by the first magnetized wheel, the first and second magnetized 3,4i5 l,28fi Patented June 24, I969 formed of a blade 3 and a ruby pallet 4. The latter drives a ratchet wheel 5 having a large number of teeth in the shape of isosceles triangles.

A second click fixed to the frame of the watch and constituted by a blade 6 carrying at its extremity a ruby pallet 7, plays the role of a retaining member, immobilizing the wheel 5 when it is not driven by the resonator.

The wheel 5 carries on its shaft Ia magnetized polar wheel 8 cut so as to have six poles 9 alternately south and north. This wheel 8 is consituted by an alloy of platinum cobalt of very high magnetic strength. Although the wheel 8 is about ten times more thick than the ratchet wheel 5, its moment of inertia is only half the moment of inertia of the wheel 5, because of its small diameter. By its rotation, the magnetized polar wheel 8 drives a wheel 10 of large diameter, constituting the first wheel of the dial train. The wheel 10 is constituted of a toothed crown 11, magnetized in the same manner as the wheel 8, mounted on a brass disc 12. Its rim is cut so as to form polar teeth 13 homologous to the poles 9 of the Wheel 8. The driving of the wheel 10 by the wheel 9 takes place in a known manner which will not be described in any more detail.

In order to disturb as little as possible the oscillation of the resonator 1 when the wheel 10 is locked or when it is made to turn in the opposite direction to that in which it turns when it is driven by the polar wheel, for example during setting of the time, the magnetic coupling between the wheels 8 and 10 is not chosen too high. In a practical embodiment for a wrist watch, an airgap is provided between the poles 9 and the corresponding poles of the wheel 10 sufiicient so that the power transmitted is approximately equal to one microwatt (1 ,u.W.). This power is sufficient to drive the wheel 10 and the gear train, and also a date device, but it is negligible with respect to the power supplied by the resonator. During braking of the wheel 10 this demand on the battery of 1 ,uW. is also negligible.

This device for transforming the movement has the advantage of being of great simplicity, of avoiding to a large degree losses of power due to friction, and of constituting an excellent mechanical filter isolating the resonator [from the gear train. Moreover, the precision of the wheels 8 and 10 can be much lower than that of wheels of mechanical engagement. Thus it is possible to make entirely independently, on the one hand the oscillator with its device for transforming the movement comprising the click, the ratchet wheel and its polar wheel 8, and on the other hand the gear train mounted on the plate and including the wheel 10, and to assemble then without difliculty these two parts.

It is understood that the drawing represents only one example of an embodiment of numerous possible variants, for example, in the number of teeth of the wheels 8 and 10, in their shapes and in their gear ratio etc.

In a cheaper embodiment, the wheel 10 can be made in la ferro-nickel alley or even in soft iron.

What is claimed is:

1. A device for transforming oscillatory movement of a normally vibrating resonator of an electronic watch into a continuous, smooth, rotatory movement, the device comprising:

(A) a click rigidly secured to said resonator;

(B) a ratchet wheel rotationally driven by said click and having a given moment of inertia;

(C) a first wheel having magnetizable poles disposed around its periphery and having a moment of inertia about one-half that of said ratchet wheel, said wheel being positioned in a given plane;

(D) the first wheel being mounted coaxially with the ratchet wheel for rotation in a normal direction;

(E) a second Wheel having a magnetizable periphery;

(F) at least one of said magnetizable wheels comprising material of high magnetic force and having poles of alternate polarity;

(G) the second wheel being positioned in the same plane as said first wheel and being adapted to be driven magnetically by the first wheel; said second wheel being rotatable against or lockable relative to said first wheel when said watch is set;

(H) an air gap separating said first and second wheels from each other, said air gap being so dimensioned that the power transmitted from said first wheel to said second wheel be suificient to drive said second wheel and hence said watch but negligible with respect to the power supplied by said resonator, to said first wheel, whereby locking or rotation of said second wheel relative to said first wheel do not interfere with the normal vibration of said resonator.

2. A device for transforming oscillatory movement of a normally vibrating resonator of an electronic Watch into a continuous, smooth, rotary movement, the device comprising:

(A) a click rigidly secured to said resonator;

(B) a ratchet wheel rotationally driven by said click and having a given moment of inertia;

(C) a first wheel having magnetizable poles disposed around its periphery and having a lesser moment of inertia than said ratchet wheel, said wheel being positioned in a given plane;

(D) the first wheel being about ten times thicker than said ratchet wheel and being mounted coaxially with the ratchet wheel for rotation in a normal direction;

- (E) a second wheel having a magnetizable periphery;

(F) at least one of said magnetizable wheels comprising material of high magnetic force and having poles of alternate polarity;

(G) the second wheel being positioned in the same plane as said first wheel and being adapted to be driven magnetically by the first wheel; said second wheel being rotatable against or lockable relative to said first wheel when said watch is set;

(H) an air gap separating said first and second wheels from each other, said air gap being so dimensioned that the power transmitted from said \first wheel to said second wheel be sufficient to drive said second wheel and hence said watch but negligible with respect to the power supplied by said resonator, to said first wheel, whereby locking or rotation of said second wheel relative to said first wheel do not interfere with the normal vibration of said resonator.

3. A device for transforming oscillatory movement of a normally vibrating resonator of an electronic watch into a continuous, smooth, rotary movement, the device comprising:

(A) a click rigidly secured to said resonator;

(B) a ratchet wheel rotationally driven by said click and having a given moment of inertia;

(C) a first wheel having magnetizable poles disposed around its periphery and having a lesser moment of inertia than said ratchet wheel, said wheel being positioned in a given plane;

(D) the first wheel being mounted coaxially with the ratchet wheel for rotation in a normal direction;

(E) a second wheel having a magnetizable periphery;

(F) at least one of said magnetizable wheels comprising material of high magnetic force and having poles of alternate polarity;

(G) the second wheel being positioned in the same plane as said first wheel and being adapted to be .4 and sufficient to drive said second wheel and hence said watch but negligible with respect to the power supplied by said resonator, to said first wheel, whereby locking or rotation of said second wheel relative to said first wheel do not interfere with the normal vibration of said resonator.

4. A device for transforming oscillatory movement of a resonator for an electronic Watch into a continuous, smooth, rotary movement, the device comprising:

(A) a click rigidly secured to the resonator,

(B) a ratchet wheel rotationally driven by said click and having a given moment of inertia and a given thickness, 7

(C) a first wheel having magnetized poles disposed around its periphery and having a moment of inertia one half that of said ratchet wheel, but a greater thickness,

(D) the first wheel being mounted coaxially with the ratchet wheel for rotation therewith,

(E) a second wheel having magnetized poles disposed around its periphery,

(F) the polarity of each pole of the first and second wheels being constant, and the polarities of adjacent poles around the peripheries of the first and second wheels being opposite,

(G) the second wheel being positioned adjacent to the first wheel and being adapted to be driven magnetically by the first wheel,

(H) the poles of said first and the second wheels being mechanically separated from each other so that one of the wheels can rotate independently of the other 7 wheel. a

5. A device for transforming oscillatory movement of a resonator for an electronic watch into a continuous, smooth, rotary movement, the device comprising:

(A) a click rigidly secured to the resonator,

(B) a ratchet wheel rotationally driven by said click and having a given moment of inertia and a given thickness,

(C) a first wheel having magnetized poles disposed around its periphery and having a lesser moment of inertia than said ratchet wheel, and having a thickness ten times thicker than the thickness of said ratchet wheel,

(D) the first wheel being mounted coaxially with the ratchet wheel tor rotation therewith,

(E) a second wheel having magnetized poles disposed around its periphery,

(F) the second wheel being positioned adjacent to the first wheel and being adapted to be driven magnetically by the first wheel,

(G) the poles of said first and the second wheels being mechanically separated from each other so that one of the wheels can rotate independently of the other wheel.

6. A device for transforming oscillatory movement of a resonator tor an electronic watch into a continuous, smooth, rotary movement, the device comprising:

(A) a click rigidly secured to the resonator,

(B) a ratchet wheel rotationally driven by said click and having a given moment of inertia and a given thickness,

(C) a first wheel having magnetized poles disposed around its periphery and having a lesser moment of inertia than said ratchet wheel, but a. greater thickness,

(D) the first wheel being mounted coaxially with the ratchet wheel for rotation therewith,

(E) a second wheel having magnetized poles disposed around its periphery,

(F) the second wheel being positioned adjacent to the first wheel and being adapted to be driven magnetically by the first wheel,

(G) the poles of said first and the second wheels being mechanically separated from each other so that one 5 6 of the wheels can rotate independently of the other FOREIGN PATENTS Wheel, 319,707 4/1957 Switzerland.

(H) an air gap provided "between said poles of said first wheel and of said second wheel, said gap having a k dimension such that the magnetic coupling power FRED MATTERN Primary Exammer' transmitted is about equal to 1 miorowatt. 5 SHOEMAKER, Assistant Examiner- References Cited US. Cl. X.R. UNITED STATES PATENTS 58*23, 116; 2,481,360 9/1949 Sprenger. 10

3,184,981 5/1965 Bennett et a1 74-142 

